Xerographic micro assembly is a method of fabricating devices using xerographic like, electrostatic force based directed assembly techniques to assemble functional micro objects to complex device structure. Mobile micro objects may be immersed in an assembly medium that covers an electrode array. An electric field pattern may be applied to the electrode array that attracts the mobile micro objects. The electric field pattern may attract or repel the mobile micro objects, which may guide the mobile micro objects into a specific position and orientation above the electrode array.